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CN Tower

Toronto, Ontario

1977 Award of Excellence from the Association of Consulting Engineers of Canada

Photo credits : Vincent Brière (2022)


Canadian National

Type of use

Telecommunications, tourism

Number of floors

Height : 553 m

Year of construction


Work type

New structure


63 M$

At 555 metres, the CN Tower is one of the tallest free-standing structures in the world. It accommodates antennas and various equipment for radio transmission, broadcasting, and telecommunications. The observation pod level includes a rotating restaurant and two floors dedicated to welcoming visitors. The tower consists of a vertically pre-stressed multi-cellular concrete mast.

The upper 107 metres comprising the actual antenna consist of a cylindrical metal frame. 39 hexagonal tube sections were brought to the site by helicopter. The joints were made with high-strength bolts. In 1995, the American Society of Civil Engineers declared this unique structure to be one of the “seven wonders of the modern world”.

For this project, NCK was contracted to provide complete structural engineering consulting services.